Composition of the spindle pole body of Saccharomyces cerevisiae and the proteins involved in its duplication.

The microtubule-organizing center (MTOC) is the organelle that manages the distribution of microtubule filaments in the cell. It includes such centers of microtubule organization as basal bodies, nucleus-associated bodies, spindle pole bodies and centrosomes. The centrosome is the MTOC in most animal cells. Despite the numerous studies that have been published on this organelle over the past 100 years, the protein composition of the animal centrosome remains poorly defined. In order to study the MTOC, many researchers have chosen the budding yeast Saccharomyces cerevisiae as a model organism. This review summarizes the budding yeast MTOC, referred to as the spindle pole body (SPB), including its structure and function, its components and the factors involved in its duplication. Electron microscopy and high-voltage electron tomographic analysis of this organelle have contributed to the understanding of its morphology, whereas analysis by matrix-assisted laser desorption/ionization has played a major role in identifying many of the spindle pole components. In addition, genetic and biochemical studies have revealed the functional and physical relationships of certain spindle pole components and proteins important for SPB duplication.